tsvwg Meeting Minutes

Summary

The TSVWG meeting covered a range of topics, including updates on existing drafts, discussion of new liaison statements, and explorations of potential new work items. Key discussion points revolved around UDP ECN implementation, user experiment drafts, Q-log integration with careful resume, L4S deployment, and DTLS for SCTP. The meeting concluded with a call for more engagement on the DTLS for SCTP topic and plans for further discussion at the next session.

Key Discussion Points

UDP ECN Implementation: Discussed platform-specific differences in socket API behavior and the desire for Apple review of the UDP ECN draft. Concerns were raised and addressed around the TOS field and dual-stack socket handling.
User Experiments Draft: Update provided on progress and specific request for reviews from those familiar with Stun and Turn.
Q-log Integration with Careful Resume: Decision to separate Q-log aspects into a separate draft. Initial discussion about adopting the Q-Log document.
L4S Deployment: Deployment update presented by Jason Livinggood. Deployment health monitoring and downstream AQM observations were highlighted.
DTLS for SCTP: A detailed review of different DTLS options, highlighting concerns about implementation complexity, formal verification, and IPR considerations.

Decisions and Action Items

UDP ECN Implementation:
- Martin to address open GitHub issues regarding argument size in C messages.
- Stuart Cheshire to review the draft from an Apple perspective.
NQB Draft:
- The document author to change the language from normative to informative regarding other SDOs.
- The working group to send a liaison statement to relevant SDOs (e.g., 3GPP) regarding NQB functionality.
Careful Resume Draft:
- Martin to review the latest draft version.
Q-Log Draft:
- A poll was conducted and the results will be confirmed by email to see if the group will adopt Q-Log draft.
DTLS for SCTP:
- A design team will be formed to discuss and propose a solution for DTLS for SCTP.

Next Steps

UDP ECN Implementation: Revise draft based on feedback and proceed with working group last call after Apple review.
Careful Resume Draft: Shepherd to move forward with IESG review.
User Experiments Draft: Working group chairs to progress draft after review of updated version.
L4S-OPS Draft: Submit as informational RFC after addressing security considerations and cache management to-do.
DTLS for SCTP: Form a design team to develop a recommendation for a solution. Limited discussion on Wednesday's meeting to decide to proceed with a solution.

Session Date/Time: 19 Mar 2025 08:30

tsvwg

Summary

This TSVWG meeting covered several draft specifications and solicited feedback from the working group. Key topics included DTLS and SCTP, flow queuing algorithms (FQ-PI), UDP fragmentation, low latency transport, IPsec MTU issues, and DSCP/ECN marking. The meeting also marked the departure of two co-chairs, Gorry Fairhurst and Martin Zeman, and the transition of Martin Duke to sole chair.

Key Discussion Points

DTLS and SCTP: A design team will reconvene to reach an agreement on the DTLS and SCTP drafts. If no agreement is reached by the Madrid meeting, the chair will present pros and cons of various solutions, followed by a show of hands. If no rough consensus is reached, the work will be abandoned.
FQ-PI: The working group discussed the FQ-PI (Flow Queuing with PI) draft. There were questions about the appropriateness of TSVWG as the home for this work, with suggestions that CCWG (Congestion Control Working Group) might be a better fit.
UDP Fragmentation: A draft documenting UDP fragmentation behavior across different operating systems was presented. There was discussion about recommending the use of dual-stack sockets and avoiding single-stack sockets.
Low Latency Transport: A draft addressing the problem of excessive buffering on source devices was discussed. There was strong support for the initiative and ideas on how to improve the specification.
IPsec MTU: A draft addressing MTU and fragmentation handling in IPsec was presented. The author sought feedback on potential negative impacts and alternative mechanisms.
DSCP/ECN: A draft concerning mapping 5G Quality of Service Identifiers (5QIs) to DSCP values was presented. There was a suggestion to include a discussion of L4S and ECN bits.
Stamp and ECN: A draft proposing an extension to the Stamp protocol to enable bidirectional measurements of ECN was discussed. There were concerns about potential abuse and violation of existing RFC rules regarding ECN marking.

Decisions and Action Items

DTLS and SCTP: Design team to reconvene and attempt to reach a mutually agreeable solution by the Madrid meeting. If that fails, the chair will facilitate a rough consensus determination at the Madrid meeting.
FQ-PI: Mohit Kaliliani will consult with CCWG chairs regarding the potential transfer of the FQ-PI draft to the CCWG.
UDP Fragmentation: Martin Zeman to consider adding a recommendation to use dual-stack sockets and avoid single-stack sockets.
IPsec MTU: Daniel to seek feedback from the IPSECME working group.
DSCP/ECN: Christoph to consider including a discussion of L4S and ECN bits in the draft.
New chair selection: After the new AD incoming is in position, the group will be looking for a new chair to work with Martin Duke

Next Steps

Authors to continue working on their respective drafts, incorporating feedback from the working group.
Discussions to continue on the mailing list, particularly for IPsec MTU and Stamp/ECN drafts.
The DTLS/SCTP design team to work towards a solution before the Madrid meeting.
Next meeting in Madrid.